The traditional means for securing a lamp shade to a light fixture is usually a plurality of screws around the rim of the receptacle that are tightened to engage in a recess within the neck of the lamp shade. See for example U.S. patents: Des. 259,060 to Hansen; Des. 303,435 to Mason; Des. 311,247 to Sonneman; Des. 315,946 to Hollbrook; U.S. Pat. No. 4,531,179 to Baker; and U.S. Pat. No. 4,764,855 to Fretz, III et al.
While these screws serve the purpose of attaching the lamp shade to the fixture, using the screws presents numerous problems. Manipulating these small attachment screws can be difficult by itself and is worsened by the location of the light fixture which is usually secured to a ceiling location. Furthermore, when the fixture is attached to a vibrating structure, such as a ceiling fan, the screws can loosen, causing the shade to create a vibrating noise or even worse, resulting in the shade fixture falling from the fixture. Still furthermore, the unsightly appearance of the screws detracts from the light fixtures overall appearance.
Other types of lamp shade fasteners have relied on retaining collars in the shades which generally screwably attach the bases of the shades to the sockets. See for example U.S. patents: U.S. Pat. No. 3,070,690 to Horn; U.S. Pat. No. 4,998,193 to Ching-Hui; and U.S. Pat. No. 5,122,942 to Lee. These types of fasteners also have similar problems to the side screws described above. They can be difficult to install and may loosen in a vibrating environment.
Other attempts have focussed on using side slots in the base of the shade that must be aligned to protruding prongs on the socket. See for example: U.S. Pat. No. 4,982,313 to Lupien which shows additional problems of manipulating the prongs to the slots on an overhead fixture, where vibrations can also dislodge the prongs from the slots. Additionally, this fastener requires the lamp shade to be of a unique shape and is not adaptable to the existing lamp shade designs.
A resilient clip was disclosed in U.S. Pat. No. 4,428,032 to Workman which claims to adequately secure a shade to an overhead light fixture. However, the Workman clip requires four extending prongs which must grip about the exterior of the base rim of the lamp shade. The Workman clip would not work with all the different lamp shades made by various manufacturers since there exists a relatively large deviation in the size and shape of the rims in those different lamp shades. Because there is limited movement of the prongs in the Workman clip, it would be difficult to insure a secure fit for the majority of these lamp shades. Furthermore, manipulating the lamp shade base adequately to fit within the space of the four prongs in an overhead fixture would not be easy, and it requires that an exterior canopy be fitted over the prongs to insure a secure fit and to prevent the accidental release of the lamp shade.
Thus, the need exists for a solution to the above presented problems with the prior art.